Zootaxa, a New Genus and Species of Tetrastichinae (Hymenoptera: Eulophidae)

A new genus and species of Tetrastichinae (Hymenoptera: Eulophidae) inducing galls in seed capsules of Eucalyptus

IL-KWON KIM & JOHN LA SALLE CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia School of Botany and Zoology; The Australian National University, Canberra, ACT, 0200, Australia. E-mail: [email protected]

Abstract

Leprosa milga Kim & La Salle gen. & sp. nov. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Eucalyptus seed capsules. The new species is an Australian seed gall inducer which has become established in South Africa and Italy. The relationship of Leprosa to two other genera of seed gall inducing tetrastichines, Quadrastichodella and Moona, is discussed.

Key words: Tetrastichinae, Leprosa, Quadrastichodella, Moona, Eucalyptus

Introduction

Most members of Tetrastichinae are known to be entomophagous as primary or hyper parasitoids on a wide variety of insects, as well as a few other arthropod hosts, including even spider egg sacs and nematodes (La Salle 1994). However, several species are known to be phytophagous, and these include gall inducers (La Salle 2005). Within Australia, tetrastichine gall-inducers mainly attack Eucalyptus, and a few other Myrta- ceae, and can induce galls on twigs, leaves, flower buds and seeds (Bouček 1988; Headrick et al. 1995; Noyes 2002, 2003; Kim et al. 2004; Kim et al. 2005; La Salle 2005). The vast majority of Australian tetrastichines are parasitoids, and many of them are associated with galls as inquilines or parasitoids (Bouček, 1988; La Salle 2005). Several species of gall-inducing tetrastichines were accidentally introduced from Australia to other areas, and have become invasive pests (Flock 1957; Timberlake 1957; Bouček 1988; Headrick et al. 1995; Mendel et al. 2004; Kim et al. 2005; La Salle 2005). These include Quadrastichodella nova Girault (Flock 1957; Tim- berlake, 1957), Leptocybe invasa Fisher & La Salle (Mendel et al. 2004), Epichrysocharis burwelli Schauff (Schauff & Garrison 2000), Oncastichus goughi Headrick & LaSalle (Gough 1988; Redak & Bethke 1995; Headrick et al. 1995; Gates & Schauff 2005) and Moona spermophaga (Kim et al. 2005). Among those gall-inducing tetrastichines, species in the genus Quadrastichodella and Moona spermophaga induce galls on seeds of several species of Eucalyptus and Corymbia (Bouček 1988; Ikeda 1999; La Salle 2005; Kim et al. 2005). These two genera appear closely related based on their seed-galling biology as well as morphological characters (Kim et al. 2005). Quadrastichodella species induce galls in eucalypts. The best known species is Quadrastichodella nova Girault which was first reported from California (Flock 1957; Timberlake 1957, as Flockiella eucalypti). Although Australian in origin, it is now recorded from Israel, Spain, Italy, USA, Argentina and South Africa (Noyes 2002, 2003; La Salle 2005).

Accepted by M. Gates: 14 March 2008; published: 9 Apr. 2008 63 Moona, the second genus of Tetrastichinae known to induce galls on eucalypt seeds, was described very recently from Australia. Moona spermophaga Kim & La Salle was first found from eucalypt seedlots which were exported to Argentina (Kim et al. 2005). Recently, this species was found in South Africa (Kim & La Salle, unpublished data). Recently, a third genus of Tetrastichinae which induces galls on eucalypt seeds was found in seed capsules of Eucalyptus in South Africa. As specimens could emerge along with Moona spermophaga, Quadrasti- chodella sp. and Megastigmus sp., it was not immediately apparent that this species could indeed induced galls. However, detailed studies showed that the new species sometimes emerged from seed capsules where other species were not present, so that it is assumed to be capable of inducing galls (Mrs. Ottilie Neser, per- sonal communication). Since work on the present paper began, this same new species has been found in Italy, where it also appears to be established and is causing galls on seeds of Eucalpytus sp. (L. De Marzo, pers. com.). In the present paper, this new genus and species is described as Leprosa milga Kim & La Salle gen. & sp. nov. Its relationship with the other two seed-galling genera is discussed, although more detailed phylogenetic studies are still necessary. Format. A single diagnosis and description are offered for a new genus and species combination. This is done to avoid repetition in the species and genus description because it is not yet clear what are generic or species level characters. Terminology used in this paper is taken from Gibson (1997) and Graham (1987). OOL, ocellar–ocular distance; POL, post-ocellar distance; CC, costal cell; SMV, submarginal vein; MV, marginal vein; STV, stigmal vein; PMV, postmarginal vein; PDL, pedicel; F1–4, funicular segments; C1–3, claval segments. Acronyms used in the text are as follows. ANIC, Australian National Insect Collection, CSIRO Entomol- ogy, Canberra, Australia; BMNH, The Natural History Museum, London, UK; SANC, South African National Collection of Insects, Pretoria, South Africa; USNM, United States National Museum of Natural History, Washington, D.C., USA.

Leprosa Kim & La Salle gen. nov.

Type species: Leprosa milga. Gender feminine. Etymology. The generic name comes from the Greek lepros, meaning scaly and/or rough. It refers to the coarse reticulation on the pedicel.

Leprosa milga Kim & La Salle sp. nov.

Diagnosis. Pedicel with coarse and raised reticulation; this reticulation absent on the scape. Frons with very weak frontofacial suture. Median carina with a small transverse split. Gena strongly swollen and malar sulcus strongly curved. Pronotum about 0.3 length of mid lobe of mesoscutum. Dorsellum about 2.3 times as long as propodeum. Propodeum smooth without median carina. The entire rim of propodeal spiracle exposed. Sub- marginal vein with 2 setae. Postmarginal vein about half the length of stigmal vein. Description. Female (Fig. 1–8). Body 1.3–1.9 mm. Body mainly brownish yellow with some dark brown areas and stripes. Head brownish yellow except back of the head and ocellar triangle dark brown. Antenna brown; scape mainly brownish yellow, brown apically. Pronotum with small dark area anteriorly. Scapula with dark area apically. Scutellum in anterior half with small dark area medially; the remainder brownish yellow. Mesopleuron with a dark spot ventrally. Propo- deum mainly dark except callus and postero-lateral end. Gaster with transverse brown stripes on every segment. Legs mainly pale brown.

64 · Zootaxa 1745 © 2008 Magnolia Press KIM & LA SALLE FIGURES 1–7. Leprosa milga &. 1. Antenna, inner side; 2. Pedicel, outer side; 3. Face, frontal view; 4. Mesosoma, dorsal view; 5. Mesosoma, lateral view; 6. Gaster, lateral view; 7. Forewing.

A NEW SEED GALL INDUCING TETRASTICHINAE Zootaxa 1745 © 2008 Magnolia Press · 65 Head (Fig. 3). POL approximately 8 times as long as OOL. Frons with very weak frontofacial suture; with distinctive median carina. Median carina with a small transverse crack-like suture which can be seen more clearly on a dried specimen. Antennal torulus placed lower than middle of face; slightly above the ventral line of eyes. Gena strongly swollen and malar sulcus strongly curved. Face with longitudinal furrow extending from torulus to clypeus. Clypeal margin bilobed. Antenna (Fig. 1–2) with 3 anelli and 3 funicular segments. The second anellus shorter than others and asymmetrical in lateral view, becoming thinner dorsally. The third anellus with one seta situated dorso-later- ally on the outer side. F1 (F1/pdl = 0.54–0.57) the longest; F2 very slightly shorter than F3 (F1: F2: F3 = 1.0: 0.85–0.87: 0.89–0.92). F1 longer than broad; F2 almost quadrate; F3 broader than long. Each successive segment slightly broader than preceding one (F1: F2: F3 = 1.0: 1.12–1.15: 1.35–1.39). Clava three segmented and each claval segment slightly asymmetrical with its sutures rather oblique; C3 very short and with a terminal spine which is so short that it can hardly be distinguishable from other sensillae. Pedicel with some coarse and raised reticulations, but not as coarse as seen in Quadrastichodella. Scape flattened and expanded anteriorly; not extending above the vertex. Thorax (Figs 4–5). Pronotum about 0.3 length of mid lobe of mesoscutum in dorsal view. Mesoscutum with a distinct medlian line; with 5–7 adnotaular setae. Transscutal articulation normal; not deep and wide. Scutellum with 2 dorsal setae; anterior pair situated slightly beyond the middle. Dorsellum about 2.3 times as long as propodeum, in dorsal view. Propodeum smoth without distinct median carina; the whole rim of propodeal spiracle exposed. Callus with 8–10 setae. Mesosternum nearly flat and without precoxal suture in front of trochantinal lobe. Gaster (Fig. 6) almost as long as head plus thorax. Apex of hypopygium extending about 0.27–0.28 length of gaster and reaching almost up to the posterior margin of G3. Cercus with 3 setae, all subequal in length. Wing (Fig. 7) veins light brown and without hyaline breaks. Submarginal vein with 2 dorsal setae; taper- ing apically and joining parastigma distal to proximal end of parastigma.. Marginal vein not swollen. Postmar- ginal vein about 0.5 length of stigmal vein. CC: MV: STV: PMV = 3.8–4.3: 3.8–6.0: 1.0: 0.5–0.6. Basal line of setae absent and cubital line of setae not extending past base of speculum. Speculum very small; area distal to speculum densely setose. Male unknown. Type material. Holotype &: SOUTH AFRICA WCAPE, Stellenbosch, 33.56S, 18.51E, 30.ix.2004, S. Neser. ex. galls in locules of ripe seed capsules of Eucalyptus ?camaldulensis. (ANIC) .

FIGURES 8–9. Leprosa milga and galled seeds of Eucalyptus ?camaldulensis. 8. L. milga &; 9. seeds with emergence hole in a seed capsule.

66 · Zootaxa 1745 © 2008 Magnolia Press KIM & LA SALLE 28 & Paratypes: Same collection date as Holotype (1&, SANC; 4&, ANIC); SOUTH AFRICA NCAPE, Colesberg, 30.42S, 25.07E, xi. 2003, A. Witt. ex. seed capsules of E. ?camaldulensis (2&, SANC; 15&, ANIC; 2&, USNM; 2&, BMNH); SOUTH AFRICA NCAPE, 26km SW Hanover, 31.14S, 24.15E, xi. 2003, A. Witt, ex. seed capsules of E. ?camaldulensis (2&, ANIC). Non-type material: 6& (ANIC), SOUTH AFRICA, Rietondale Exp. Stn., Pretoria, 25.43S 28.14E, 9.ix. 2005, H. Klein, ex. seed capsules of E. camaldulensis; 14& (ANIC), SOUTH AFRICA, WCape, Stellenbosch, 33.56S 18.51E, 4.xi.2005, M. Alsopp, ex. seed capsules of E. camaldulensis; 5& (ANIC), ITALY, Valenzano, Bari prov., 2.ix.2006, ex. seed capsules of E. camaldulensis; 10& (ANIC), ITALY, Valenzano, Bari prov., 18.xii.2006, ex. seed capsules of E. camaldulensis; 6& (ANIC), ITALY, Valenzano, Bari prov., 2.xii.2007, from flowers of E. camaldulensis. Etymology. The species name milga comes from an Australian aboriginal word, meaning of seed. It denotes the seed-galling biology of the species. Biology. Emerged from seed capsules of E. ?camadulensis. Distribution. Described from specimens from South Africa and Italy. Although we have yet to obtain specimens from Australia, we are assuming from its relationship to the endemic Australian genera Quadrasti- chodella and Moona that it is Australian in origin.

Discussion

With the description of Leprosa, three seed-galling genera of tetrastichines are now known: Leprosa, Quad- rastichodella and Moona. Leprosa milga appears related to Quadrastichodella and Moona based on the fol- lowing shared characters: the postmarginal vein about half length of stigmal vein; the pronotum about 0.3 the length of the mesoscutum; the gena strongly swollen and the malar sulcus strongly curved; the propodeum smooth and shorter than or as long as the dorsellum; gall inducers in eucalypt seeds. Leprosa differs from Quadrastichodella and Moona as follows: median carina on the scrobal depression with a small transverse suture (Quadrastichodella with such a suture but Moona without it), antenna with 3 anelli (Quadrastichodella and Moona with 4 anelli), the third anellus with a large, dorsal seta (Quadrasti- chodella and Moona without a seta on anelli), submarginal vein with 2 setae (Quadrastichodella and Moona with more than 3 setae), the whole rim of the propodeal spiracle exposed (Quadrastichodella and Moona with a spiracle at least partially covered by the raised lobe of the callus), the mesosternum in front of the trochantinal lobe flat. One interesting feature is that this new species has coarse reticulation on the pedicel, but not on the scape. Quadrastichodella has coarse reticulation on both pedicel and scape, while Moona lacks coarse reticulation on either structure. The relationship of Leprosa to Quadrastichodella and Moona still remains ambiguous. Further intensive phylogenetic study is required for better hypotheses on the relationships among these seed gall-inducing tetrastichine genera.

Acknowledgments

We would like to thank Mrs. Ottilie Neser, Biosystematics Division, ARC-Plant Protection Research Institute, Pretoria, South Africa, and Dr. Luigi De Marzo, Università della Basilicata, Potenza, Italy for providing valu- able materials and biological information for this study.

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